Even after a few years, broat cars would likely still be relevant because there would still be places with rough roads—like in farms—people would have to go to.
Alterra's farms weren't small even as a village, let alone now that it was a town with several times more land area. If one were to look at the overall layout of Alterra, the total land the farmlands took up would probably be bigger than the area of a level 3 village.
They had also been training the broats like horses, so that their people could ride them if they wanted to go elsewhere, but not spend much energy.
They'd probably be useful as mounts only for people below level 15, though, as people beyond that level would be faster on their own with not much energy differences.
